I just recently came across this great and concise summary explaining the different facets of these classification systems that are floating around the BIM world to help structure the information. Go to the Mitchell Brandtman 5D Quantity Surveyors website to see the full article ..

So many classification systems.

There is much discussion in the world about BIM and what it is and isn’t and what it’s supposed to achieve.
For designers the pathway is not clear and common questions that arise are: How should I classify information? What codes should I include with my families? What codes are useful for estimating and quantity take-off?
During our time in this field which spans 20 years but more recently has become intensive in the last 10 years, we have discovered a range of resources that demonstrate credible frameworks for BIM and act as a benchmark to what we think will become best practice in the area of building information modeling.
Coding
There is no golden code.
In circulation today there are a number of different coding systems but we are yet to locate a published industry code that is suitable for becoming a price code which will automatically link a rate to a specific system or assembly. UniFormat II is one example and while it is close to achieving this goal it has insufficient levels to specifically identify the material and fixing condition.
All of the classification systems in the world fall into 4 groups, elements, trades, products and functions.
Elements (cost): ACMM2 or “QSID”(AUS), UniFormat II(US), COBie2 Table 21(US), Uniclass Table G(UK), BCIS4(UK)
Trades (specifications & subcontracting) NATSPEC(AUS), ASMM5(AUS), MasterFormat(US), Uniclass Table J & K(UK)
Products (supplier library) Ominclass(US), COBie2 Table 23(US), Uniclass Table L(UK)
Functions (benchmarking & usage) COBie2 Table 11 & 13(US), Uniclass Table D & F(UK)
It’s important to understand that Cobie is not one code. It is 8 – 9 different tables and encompasses all of the (4) groups above.
The available codes are useful for organising information in a logical order and for analysing costs at an elemental level to enable consistent benchmarking and reporting of project costs. Each system has been developed for a different purpose and the best results can be achieved by using them in combination.
For these reasons Mitchell Brandtman consults with the project partners to identify the most appropriate combination to apply for each specific project which is pushed into the models as a set of instance parameters.
Making QSID Redundant
Within the architectural and design space the developing requirement for QSID is causing a lot of industry confusion and angst. QSID is not a classification system in itself, it is a very basic coding system, just two digits of the elemental coding that is the Australian Cost Control Manual (ACMM2) maintained by the Australian Institute of Quantity Surveyors (AIQS). The project QS should be capable of pulling information from any model (at any stage) and pushing back or “round-tripping” accurate codes and data at the right time to alleviate the need for designers to input codes like QSID.
Using a 5DQS who can input its own and a combination of other more robust codes and “round-trip” the data to the model provides far greater benefit. It immediately creates a model map that can be used by all project partners including the contractor and subcontractors as well as the designers and programmers at any point through the process.
Classification Systems
Here is what we think is a simple explanation of the various classification systems and where you can find the codes to decide for yourself. Each system has been developed for a different purpose and the best results can be achieved by using them in combination.
Many of the current BIM Guidelines and BIM Execution Plans refer to OmniClass, MasterFormat and UniFormat to name and code objects or families. These systems were developed by the US based Construction Specification Institute (CSI) and Construction Specifications Canada (CSC) for the construction industry and can be used to structure construction data attached to a model.
If you are interested in Classification Systems for BIM, join the Linked In discussions on this topic.